The invention relates in one embodiment to a field effect transistor having at least one layer that consists of or comprises a III-V compound semiconductor, wherein the compound semiconductor comprises at least one element from the chemical group III being selected from any of gallium, aluminium, indium and/or boron and also comprises at least one element from the chemical group V being selected from nitrogen, phosphorous and/or arsenic and comprises at least nitrogen.
In another embodiment, the invention relates to a method for manufacturing a field effect transistor having at least one layer that consists of or comprises a III-V compound semi-conductor, wherein the compound semiconductor comprises at least one element from the chemical group III being selected from any of gallium, aluminium, indium and/or boron and also comprises at least one element from the chemical group V being selected from nitrogen, phosphorous and/or arsenic.
US 2005/0236646 A1 discloses a field effect transistor. Said known field effect transistor comprises a plurality of layers that each comprise different III-V compound semiconductors. The source and drain contacts of the known field effect transistor are manufactured by metal layers that are deposited on the surface of the semiconductor material. Subsequent tempering partially diffuses the metal into the semiconductor material, so that doped regions form in the adjoining semiconductor material, thereby allowing a predefined resistive response from the contact.
However, this known field effect transistor has the disadvantage that the depth of penetration may be controlled only inadequately due to the diffusion process. Usually, the depth of penetration amounts several μm, but at least 1 μm. Thus, the structural size of a known field effect transistor is relatively high, which means that integrated circuits may be built only with low complexity. Finally, the contact may diffuse into the semiconductor material to such an extend that an unwanted parasitic current flow may be formed parallel to the channel of the field effect transistor. In this case, the field effect transistor is usually out of specifications and has to be discarded. This increases production scrap and lowers the yield of the manufacturing process.
Therefore, it is an object of the invention to provide a field effect transistor and a method for its production with lower production scrap and higher yield of the manufacturing process.